Ignition Light

[Monty]

Guys 1st Post so be gentle

I have a Bond Mk2 with a 2500 engine that's been upgraded to Alternator. Simple issue being that the ignition Light is full on with ignition switch on and when the engine is started it goes dim but its still on. when its fitted into the speedo behind the red gem, it can only be seen at night or I shade the front of the speedo. Its been like this for months and seems to be charging as the volt gauge is showing 12.5 -14 volts running, no problem with flat batteries all over the winter with very little running.

I'm sure I have seen a check for the alternator with a separate lamp, I have 2 connections on the back. Any simple explanation of how this lamp works.

I Have a switched white going to the lamp with 12V then a brown and yellow on the other side that disappears into the loom.

 

[Pete Lewis]

With it going dim when running you have a diode failed in the rectifier pack

Pete

[Monty]

any way to test it

[Pete Lewis]

You need a simple meter,  and with diode  and regulator pack removed or at least uncovered to access the cooling plate pack with the diodes bonded into,  set meter on resistance /ohms  and one probe on plate one on the diode wire , then reverse the probes 

There should only be a reading in one direction if one of the small diodes reads both ways its failed

Unscrupulous reconditioners would snip the wire , solves the problem but reduces the output capacity

Depends on make but most have repair kits to replace the packs , some alternators are quite cheap and not worth messing with

as you fit a replace,   kit then find the bearing are going the same way the following month.

 

[Monty]

Thanks for that I did a voltage check tonight and it’s just a tad low 13.1 ish lights on it dips but comes back to the same. Set up a test light and the result is the same strait off the back of the alternator, so loom is ruled out. I did the diode check strait off the big spade and the case and it was open both ways so I think you are correct O wise one thanks

[Monty]

Another payment out of  the Triumph fund to get an extra 1 volt. dashbord light off at a tad over 14.5  on tickover and a slight drop when lights radio and fan on but only for a few seconds than back to 14+. I will look at a repair kit for the Lucas one 

Thanks for the help